Mr. Lee originally trained in Wing Chun. He studied under Yip Man who is famous for Wing Chun. Bruce Lee never completed the wing chun system when he moved to the United States. Bruce Lee started to teach Wing Chun or as he called it Jun Faun Kung Fu in the United States. Jun Faun was Bruce Lee's Chinese given name.
Bruce Lee was interested in a lot of various martial arts and physical training. There has been many stories why Bruce Lee started his new development of Jeet Kune Do. The most famous of the stories is when he was told he could not teach Non Chinese people Chinese martial arts. When he refused... he was given an challenge. If he won the fight he could teach who he wanted. If he lost he would stop teaching. And hence the story oh fighting Wong Jack Man is told. Wong Jack Man was the person who was sent to challenge Bruce. Bruce won the fight but was highly discouraged in his performance. He found himself winded, tired, exhausted from the fight. He felt the fight should have been over in less than a minute but instead lasted for several minutes.
This was the reason that Bruce cultivated and developed Jeet Kune Do. He personally felt that traditional martial arts were too rigid, imobile and not as effective as they use to be.
Bruce Lee took principles from mainly three different martial arts. Boxing, Fencing, and Wing Chun.
Bruce Lee admired Muhammid Ali and his foot work. He also liked the principle of striking first and putting your strong side forward from fencing. Bruce pulled a lot from Wing Chun and mixed the three arts. It's not to say that Bruce limited his research to just these three arts.
Bruce was a philospher. He was just not a fighter. He was a great thinker, a great motivator. In fact many people say Bruce Lee was not gifted with super man like physical attributes, but that he motivated himself to be the best that he could be. Each goal was replaced with a higher goal. He was always learning and moving forward.
Bruce Lee was definitely a great man. Not just in the world of martial arts. But in sense of spirit. His spirit often amazed people. He was charasmatic. He inspired so many people then... and still does 40 plus years since his death...